DOCSLIB.ORG

Piezoelectricity in PVDF and PVDF Based Piezoelectric Nanogenerator: a Concept

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Piezoelectricity in PVDF and PVDF Based Piezoelectric Nanogenerator: a Concept IOSR Journal of Applied Physics (IOSR-JAP) e-ISSN: 2278-4861.Volume 9, Issue 3 Ver. I (May. – June. 2017), PP 95-99 www.iosrjournals.org Piezoelectricity in PVDF and PVDF Based Piezoelectric Nanogenerator: A Concept Binoy Bera1,*, Madhumita Das Sarkar2 1,2Department of computer science and engineering, West Bengal University of Technology, Kolkata – 700064, India Abstract: Polyvinylidene fluoride or simply PVDF is one of the most important semicrystalline polymers which generate piezoelectricity when a pressure or mechanical force applied on it. It has four crystalline phases α, β, ɣ and δ depending on the chain conformation structure. Among them α is non polar phase and β and ɣ are polar phase. Piezoelectricity in PVDF arises due to the β and ɣ phase formation. Several materials have been introduced for the preparation of nanogenerator. Among them PVDF (polyvinylidene fluoride) is most interesting material used in nanogenerator preparation due to its flexibility, bio- compatiable, nontoxic in nature. It is used in nanogenerator application due to its good ferroelectric, piezoelectric and pyroelectric properties. In this article we describe little bit concept about PVDF, its piezoelectricity and PVDF based nanogenerator. Application of piezoelectric nanogenerator is also briefly described here. Keywords: PVDF, nanogenerator, piezoelectricity, β phase, electrospinning, electroactive phase, Poling process. I. Introduction Polyvinylidene fluoride, or polyvinylidene difluoride, (PVDF) is a highly non- reactive thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. PVDF has four crystalline phases α, β, ɣ and δ depending on the chain conformation. Among them α is thermodynamically most stable and non polar in nature. β and ɣ are polar phase. Non polar PVDF is used as insulator and painting. Polar PVDF is used in energy harvesting, sensor, actuator, electronics e.t.c. PVDF has several properties like biocompatiable, chemical resistance, good film forming capability, cost effictiveness e.t.c.. Among four crystalline phase β is of great importance due to its spontaneous polarization and piezoelectric sensitivity. Because of this property tremendous effort has been paid to induce electroactive β phase in PVDF. Several methods are there to induce β phase in PVDF. It can be achieved by placing it into a high electric field which randomly orient CH2/CF2 dipoles along with the electrical field direction. Different types of doping (like metal nanoparticle , hydrated salt for avoiding poling step) also done for achieving electroactive phase. The dielectric constant of PVDF is also high about 12, which makes it suitable to integrate in device for getting singnal to noise ratio less. It has glass transition temperature of -350C which is much less than room temperature. So it is much flexible in room temperature. Now a days PVDF is largely used in nanogenerator application due to its piezoelectricity. PVDF is non toxic, flexible, easy to process make it suitable in nanogenerator application. PVDF or polyvinylidene fluoride is a polymer material which shows piezoelectricity when pressure or mechanical force applied on it. The material which shows piezoelectricity is called piezoelectric material. Piezoelectric material can be of crystals, ceramics or polymer. Piezoelectric crystals are like quartz, berilinite, gallium orthophosphate, and tourmaline. Piezoelectric ceramics are like barium titanate, lead zirconate titanate, barium zirconate titanate. Some polymer (PVDF, PVDF - TrFE) also shows piezoelectric effect. Based on this properties a new type technology arises today. This is called nanogenerator. A nanogenerator is a type of device which generates voltage or power when a mechanical force or vibration applied on it. Among all piezoelectric material, polymer like PVDF is most suitable because it is nontoxic, flexible, bio- compatiable, high piezoelectric voltage constant. As already told PVDF exists in several forms: alpha (TGTG'), beta (TTTT), gamma (TTTGTTTG') and δ phases, depending on the chain conformations as trans (T) or gauche (G) linkages. Among them α does not show piezoelectric properties. β, ɣ and δ phase show piezoelectric properties. Generally PVDF is present in non polar(α) phase. To make PVDF polar, several approaches are there like stretching, metal nanoparticle doping, hydrated salt dpoing, electrospinning process e.t.c. Among all polar phase β phase is most important due to its high remnant polarization and highest dipolar moment per unit cell (8 × 10−30 C m) when compared to the other two phases. FTIR, bands and X-ray diffraction peaks typically used for the identification of the phases. Many researchers are paying attention to nanogenerators (NGs) as energy source in self-powered mirco-nano system. Now a days device are gradually decreasing in size and they need small power. In that case nanogenerator is useful as it generates voltage in the range of micro and nano order. It is also used in small battery charging, wireless power transmission, LED light glow e.t.c. DOI: 10.9790/4861-0903019599 www.iosrjournals.org 95 | Page Piezoelectricity in PVDF and PVDF Based Piezoelectric Nanogenerator: A Concept Fig.1. Different application of nanogenerator II. PVDF Polyvinylidene fluoride, or polyvinylidene difluoride, (PVDF) is a highly non- reactive thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. As already told it has four crystalline phase depending on chain conformation structure. When poled, PVDF is a ferroelectric polymer, exhibiting efficient piezoelectric and pyroelectric properties. These characteristics make it useful in sensor and battery applications. PVDF has a glass transition temperature (Tg) of about −35 °C and is typically 50–60% crystalline. Unlike other popular piezoelectric materials, such as PZT (lead zirconate titanate), PVDF has a negative d33 value. Physically, this means that PVDF will compress instead of expand or vice versa when exposed to the same electric field. PVDF is a specialty plastic used in applications requiring the highest purity, as well as resistance to solvents, acids and bases. Compared to other fluoropolymers, like polytetrafluoroethylene (Teflon), PVDF has a low density (1.78 g/cm3). It is available as piping products, sheet, tubing, films, plate and an insulator for premium wire. It can be injected, molded or welded and is commonly used in the chemical, semiconductor, medical and defense industries, as well as in lithium-ion batteries. It is also available as a crosslinked closed-cell foam, used increasingly in aviation and aerospace applications. Fig.2. The three primary polymorphic crystalline phases of PVDF III. How Piezoelectricity Generates Piezoelectricity is the ability of certain material to generate electrical voltage when a mechanical force or pressure applied on it. Material which shows this kind of behavior is called piezoelectric material. PVDF is also a piezoelectric polymer material. As already mentioned, α phase of PVDF is non polar, so it does not show piezoelectric effect. β and ɣ phase are responsible for generating piezoelectricity in it. Normally the charges of piezoelectric crystals are in balanced even they are not symmetrically arranged. The effects of charges are exactly cancel out, leaving no net charges in it. When a pressure or mechanical force applied on it, the charges are become out of balance. This effect of charges does not cancel each other, so net charges appears on both side of crystals. Such this way a voltage can be generate in it by simply pressing it. Now the piezoelectricity generation are depend on electroactive pahse and crystallinity of PVDF material. Normally PVDF material is not piezoelectric because it is in non polar phase. It is produced in large thin clear sheets which are then stretched and poled to give it the piezoelectric properties. Materials that have crystalline lattice structure, that is DOI: 10.9790/4861-0903019599 www.iosrjournals.org 96 | Page Piezoelectricity in PVDF and PVDF Based Piezoelectric Nanogenerator: A Concept a three dimensional geometric arrangement of atoms in a molecule which repeats itself from molecule to molecule (unit cell). Piezoceramics are solid mixtures of minute piezo crystallites. Dipoles are randomly oriented initially. Repsonses of these dipoles to externally applied electric field would tend to cancel one another, producing no gross change in the dimensions of the piezoceramics. They do not have piezoelectric behavior at macro level. In order to obtain a useful macroscopic piezoelectric response, dipoles must be permanently aligned with one another. A process called poling is used for this purpose. A piezoelectric material has a characteristic Curie temperature. When heated above this temperature, dipoles can change oriention in the solid phase of the material. In poling process, material is heated above its Curie temperature and a strong electric field is applied. Direction of the electric field is the polarization direction and the dipoles shift into alignment with it. Keeping the electric field constant, material is cooled below its Curie temperature , with the results that the alignment of dipoles is permanently fixed. In this case, material is said to be poled. Fig.3. The electric field is in the opposite direction of the poled direction and the sheet is stretched length. Fig.4. the electric field is in the same direction of the poled direction and the sheet is contracted in length. IV. Nanogenerator A Nanogenerator is
Load more

Recommended publications
  • Fluorinated Polymers As Smart Materials for Advanced Biomedical Applications
    polymers Review Fluorinated Polymers as Smart Materials for Advanced Biomedical Applications Vanessa F. Cardoso 1,2,* ID , Daniela M. Correia 3,4, Clarisse Ribeiro 1,5 ID , Margarida M. Fernandes 1,5 and Senentxu Lanceros-Méndez 4,6 1 Centro/Departamento de Física, Universidade do Minho, 4710-057 Braga, Portugal; cribeiro@fisica.uminho.pt (C.R.); margaridafernandes@fisica.uminho.pt (M.M.F.) 2 CMEMS-UMinho, Universidade do Minho, DEI, 4800-058 Guimaraes, Portugal 3 Departamento de Química e CQ-VR, Universidade de Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal; [email protected] 4 BCMaterials, Basque Center for Materials, Applications and Nanostructures, UPV/EHU Science Park, 48940 Leioa, Spain; [email protected] 5 CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal 6 IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain * Correspondence: [email protected]; Tel.: +351-253-60-40-73 Received: 11 January 2018; Accepted: 6 February 2018; Published: 8 February 2018 Abstract: Fluorinated polymers constitute a unique class of materials that exhibit a combination of suitable properties for a wide range of applications, which mainly arise from their outstanding chemical resistance, thermal stability, low friction coefficients and electrical properties. Furthermore, those presenting stimuli-responsive properties have found widespread industrial and commercial applications, based on their ability to change in a controlled fashion one or more of their physicochemical properties, in response to single or multiple external stimuli such as light, temperature, electrical and magnetic fields, pH and/or biological signals. In particular, some fluorinated polymers have been intensively investigated and applied due to their piezoelectric, pyroelectric and ferroelectric properties in biomedical applications including controlled drug delivery systems, tissue engineering, microfluidic and artificial muscle actuators, among others.
    [Show full text]
  • Poly[4(5)-Vinylimidazole]/Polyvinylidene Fluoride Composites As Proton Exchange Membranes Jingjing Pan
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by RIT Scholar Works Rochester Institute of Technology RIT Scholar Works Theses Thesis/Dissertation Collections 4-1-2009 Poly[4(5)-vinylimidazole]/polyvinylidene fluoride composites as proton exchange membranes Jingjing Pan Follow this and additional works at: http://scholarworks.rit.edu/theses Recommended Citation Pan, Jingjing, "Poly[4(5)-vinylimidazole]/polyvinylidene fluoride composites as proton exchange membranes" (2009). Thesis. Rochester Institute of Technology. Accessed from This Thesis is brought to you for free and open access by the Thesis/Dissertation Collections at RIT Scholar Works. It has been accepted for inclusion in Theses by an authorized administrator of RIT Scholar Works. For more information, please contact [email protected]. Poly[4(5)-Vinylimidazole]/Polyvinylidene Fluoride Composites as Proton Exchange Membranes Jingjing Pan April 2009 Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Chemistry. Approved: _______________________________________ Thomas W. Smith (Advisor) ______________________________ Paul Rosenberg (Department Head) Department of Chemistry Rochester Institute of Technology Rochester, New York 14623-5603 Copyright Release Form: INVESTIGATION OF POLY[4(5)-VINYLIMIDAZOLE] COMPOSITES AND THEIR POTENTIAL AS PROTON CONDUCTIVE MEMBRANES I, Jingjing Pan, hereby grant permission to the Wallace Memorial Library of Rochester Institute of Technology to reproduce my thesis in whole or in part. Any reproduction will not be for commercial use or profit. Jingjing Pan April, 2009 i Abstract In the present research, the morphology and thermal chemical characteristics of composite films comprised of poly(vinylidene fluoride) (PVF2) and poly[4(5)-vinylimidazole/vinylimidazolium trifluoromethylsulfonylimide] (PVIm/VIm+TFSI-]) were studied.
    [Show full text]
  • High Performance Triboelectric Nanogenerator and Its Applications
    HIGH PERFORMANCE TRIBOELECTRIC NANOGENERATOR AND ITS APPLICATIONS A Dissertation Presented to The Academic Faculty by Changsheng Wu In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY in the SCHOOL OF MATERIALS SCIENCE AND ENGINEERING Georgia Institute of Technology AUGUST 2019 COPYRIGHT © 2019 BY CHANGSHENG WU HIGH PERFORMANCE TRIBOELECTRIC NANOGENERATOR AND ITS APPLICATIONS Approved by: Dr. Zhong Lin Wang, Advisor Dr. C. P. Wong School of Materials Science and School of Materials Science and Engineering Engineering Georgia Institute of Technology Georgia Institute of Technology Dr. Meilin Liu Dr. Younan Xia School of Materials Science and Department of Biomedical Engineering Engineering Georgia Institute of Technology Georgia Institute of Technology Dr. David L. McDowell School of Materials Science and Engineering Georgia Institute of Technology Date Approved: [April 25, 2019] To my family and friends ACKNOWLEDGEMENTS Firstly, I would like to express my sincere gratidue to my advisor Prof. Zhong Lin Wang for his continuous support and invaluable guidance in my research. As an exceptional researcher, he is my role model for his thorough knowledge in physics and nanotechnology, indefatigable diligence, and overwhelming passion for scientific innovation. It is my great fortune and honor in having him as my advisor and learning from him in the past four years. I would also like to thank the rest of my committee members, Prof. Liu, Prof. McDowell, Prof. Wong, and Prof. Xia for their insightful advice on my doctoral research and dissertation. My sincere thanks also go to my fellow lab mates for their strong support and help. In particular, I would not be able to start my research so smoothly without the mentorship of Dr.
    [Show full text]
  • Piezoelectric Nanogenerator Using Cds Nanowires
    APPLIED PHYSICS LETTERS 92, 022105 ͑2008͒ Piezoelectric nanogenerator using CdS nanowires ͒ ͒ Yi-Feng Lin,1,2 Jinhui Song,1 Yong Ding,1 Shih-Yuan Lu,2,b and Zhong Lin Wang1,a 1School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, USA 2Department of Chemical Engineering, Tsing Hua University, Hsinchu, Taiwan 30013, Republic of China ͑Received 2 November 2007; accepted 15 December 2007; published online 14 January 2008͒ Vertically grown cadmium sulfide ͑CdS͒ nanowire ͑NW͒ arrays were prepared using two different processes: hydrothermal and physical vapor deposition ͑PVD͒. The NWs obtained from the hydrothermal process were composed of alternating hexagonal wurtzite ͑WZ͒ and cubic zinc blende ͑ZB͒ phases with growth direction along WZ ͗0001͘ and ZB ͓111͔. The NWs produced by PVD process are single crystalline WZ phase with growth direction along ͗0001͘. These vertically grown CdS NW arrays have been used to converting mechanical energy into electricity following a developed procedure ͓Z. L. Wang and J. Song Science 312, 242 ͑2006͔͒. The basic principle of the CdS NW nanogenerator relies on the coupled piezoelectric and semiconducting properties of CdS, and the data fully support the mechanism previously proposed for ZnO NW nanogenerators and nanopiezotronics. © 2008 American Institute of Physics. ͓DOI: 10.1063/1.2831901͔ CdS is a piezoelectric semiconducting material1 with an The morphology of the hydrothermally grown CdS NWs energy band gap of about 2.5 eV. A wide range of applica- was characterized with scanning electron microscope ͑SEM͒. tions have been demonstrated for one-dimensional CdS As shown in Fig.
    [Show full text]
  • Triboelectric Nanogenerator Networks Integrated with Power Management Module for Water Wave Energy Harvesting
    FULL PAPER Blue Energy www.afm-journal.de Triboelectric Nanogenerator Networks Integrated with Power Management Module for Water Wave Energy Harvesting Xi Liang, Tao Jiang, Guoxu Liu, Tianxiao Xiao, Liang Xu, Wei Li, Fengben Xi, Chi Zhang,* and Zhong Lin Wang* by the consumption of fossil fuels have Ocean waves are one of the most promising renewable energy sources for attracted worldwide attention.[1,2] It is large-scope applications. Recently, triboelectric nanogenerator (TENG) network highly urgent to search for other renew- has been demonstrated to effectively harvest water wave energy possibly able and clean energy sources. Water toward large-scale blue energy. However, the absence of effective power wave energy, which has abundant reserves and little dependence on environmental management severely restricts the practicability of TENGs. In this work, a conditions, is a promising renewable energy hexagonal TENG network consisting of spherical TENG units based on spring- source with great potential for large-scale assisted multilayered structure, integrated with a power management module applications.[3–5] However, such energy has (PMM), is constructed for harvesting water wave energy. The output perfor- rarely been exploited due to lack of eco- mance of the TENG network is found to be determined by water wave frequen- nomical energy scavenging technologies in spite of the great efforts devoted.[6–8] cies and amplitudes, as well as the wave type. Moreover, with the implemented So far, most demonstrated converters for PMM, the TENG network could output a steady and continuous direct current water wave energy rely on the electromag- (DC) voltage on the load resistance, and the stored energy is dramatically netic generators, which are heavy, bulky, improved by up to 96 times for charging a capacitor.
    [Show full text]
  • Graphene Oxide Papers in Nanogenerators for Self-Powered
    www.nature.com/scientificreports OPEN Graphene Oxide Papers in Nanogenerators for Self-Powered Humidity Sensing by Finger Tapping Faezeh Ejehi1, Raheleh Mohammadpour1 ✉ , Elham Asadian2, Pezhman Sasanpour2,3, Somayeh Fardindoost4 & Omid Akhavan4 Triboelectric nanogenerators (TENGs) ofer an emerging market of self-sufcient power sources, converting the mechanical energy of the environment to electricity. Recently reported high power densities for the TENGs provide new applications opportunities, such as self-powered sensors. Here in this research, a fexible graphene oxide (GO) paper was fabricated through a straightforward method and utilized as the electrode of TENGs. Outstanding power density as high as 1.3 W.m−2, an open-circuit voltage up to 870 V, and a current density of 1.4 µA.cm−2 has been extracted in vertical contact-separation mode. The all-fexible TENG has been employed as a self-powered humidity sensor to investigate the efect of raising humidity on the output voltage and current by applying mechanical agitation in two forms of using a tapping device and fnger tapping. Due to the presence of superfcial functional groups on the GO paper, water molecules are inclined to be adsorbed, resulting in a considerable reduction in both generated voltage (from 144 V to 14 V) and current (from 23 µA to 3.7 µA) within the range of relative humidity of 20% to 99%. These results provide a promising applicability of the frst suggested sensitive self-powered GO TENG humidity sensor in portable/wearable electronics. Energy harvesting is an area of tremendous attention because of the huge worldwide energy demands motivating considerable research on self-powered and autonomous systems1.
    [Show full text]
  • Smart Wearable Sensors Based on Triboelectric Nanogenerator for Personal Healthcare Monitoring
    micromachines Article Smart Wearable Sensors Based on Triboelectric Nanogenerator for Personal Healthcare Monitoring Ruonan Li 1,2, Xuelian Wei 3,4, Jiahui Xu 3,4, Junhuan Chen 3, Bin Li 1, Zhiyi Wu 3,4,5,* and Zhong Lin Wang 3,4,5,6,* 1 School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; [email protected] (R.L.); [email protected] (B.L.) 2 Center on Nano-Energy Research, School of Physical Science & Technology, Guangxi University, Nanning 530004, China 3 Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, China; [email protected] (X.W.); [email protected] (J.X.); [email protected] (J.C.) 4 College of Nanoscience and Technology, University of Chinese Academy of Science, Beijing 100049, China 5 CUSPEA Institute of Technology, Wenzhou 325024, China 6 School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA * Correspondence: [email protected] (Z.W.); [email protected] (Z.L.W.) Abstract: Accurate monitoring of motion and sleep states is critical for human health assessment, especially for a healthy life, early diagnosis of diseases, and medical care. In this work, a smart wearable sensor (SWS) based on a dual-channel triboelectric nanogenerator was presented for a real-time health monitoring system. The SWS can be worn on wrists, ankles, shoes, or other parts of the body and cloth, converting mechanical triggers into electrical output. By analyzing these signals, the SWS can precisely and constantly monitor and distinguish various motion states, including stepping, walking, running, and jumping.
    [Show full text]
  • Piezoelectric-Nanowire-Enabled Power Source for Driving Wireless Microelectronics
    ARTICLE Received 4 Jun 2010 | Accepted 23 Sep 2010 | Published 19 Oct 2010 DOI: 10.1038/ncomms1098 Piezoelectric-nanowire-enabled power source for driving wireless microelectronics Sheng Xu1, Benjamin J. Hansen1 & Zhong Lin Wang1 Harvesting energy from irregular/random mechanical actions in variable and uncontrollable environments is an effective approach for powering wireless mobile electronics to meet a wide range of applications in our daily life. Piezoelectric nanowires are robust and can be stimulated by tiny physical motions/disturbances over a range of frequencies. Here, we demonstrate the first chemical epitaxial growth of PbZrxTi1 − xO3 (PZT) nanowire arrays at 230 °C and their application as high-output energy converters. The nanogenerators fabricated using a single array of PZT nanowires produce a peak output voltage of ~0.7 V, current density of 4 µA cm − 2 and an average power density of 2.8 mW cm − 3. The alternating current output of the nanogenerator is rectified, and the harvested energy is stored and later used to light up a commercial laser diode. This work demonstrates the feasibility of using nanogenerators for powering mobile and even personal microelectronics. 1 School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, USA. Correspondence and requests for materials should be addressed to Z.L.W. (email: [email protected]). NATURE COMMUNICATIONS | 1:93 | DOI: 10.1038/ncomms1098 | www.nature.com/naturecommunications © 2010 Macmillan Publishers Limited. All rights reserved. ARTICLE NatUre cOMMUNicatiONS | DOI: 10.1038/ncomms1098 he search for sustainable micro/nano-powering sources for driving wireless and mobile electronics is an emerging field in today’s energy research, which could offer a fundamental solu- T 1–3 001 tion to the energy needed for driving nanodevices/nanosystems .
    [Show full text]
  • Systematic Review Protocol for the PFBA, Pfhxa, Pfhxs, PFNA, and PFDA (Anionic and Acid Forms) IRIS Assessments
    EPA/635/R-20/131 IRIS Assessments Protocol www.epa.gov/iris Systematic Review Protocol for the PFBA, PFHxA, PFHxS, PFNA, and PFDA (anionic and acid forms) IRIS Assessments CASRN 335-76-2 (PFDA) CASRN 375-95-1 (PFNA) CASRN 307-24-4 (PFHxA) CASRN 355-46-4 (PFHxS) CASRN 375-22-4 (PFBA) Supplemental Information―Appendix A October 2019 Updated February 2020 (in response to public comments) This document was posted for public comment on November 8, 2019 (link to more information), and subsequently updated in response to those comments (updates are outlined in Section 12). It does not represent and should not be construed to represent any Agency determination or policy. Integrated Risk Information System Center for Public Health and Environmental Assessment Office of Research and Development U.S. Environmental Protection Agency Washington, DC Systematic Review Protocol for the PFBA, PFHxA, PFHxS, PFNA, and PFDA IRIS Assessments DISCLAIMER This document was posted for public comment on November 8, 2019 (link to more information), and subsequently updated in response to those comments (updates are outlined in Section 12). It does not represent and should not be construed to represent any Agency determination or policy. This document is a draft for review purposes only and does not constitute Agency policy. ii DRAFT―DO NOT CITE OR QUOTE Systematic Review Protocol for the PFBA, PFHxA, PFHxS, PFNA, and PFDA IRIS Assessments CONTENTS AUTHORS|CONTRIBUTORS|REVIEWERS .....................................................................................................
    [Show full text]
  • The Uses of Polyvinylidene Fluoride Based Resins in Chemical Handling Systems Denis K
    INTERCORR2014_306 Copyright 2014, ABRACO Trabalho apresentado durante o INTERCORR 2014, em Fortaleza/CE no mês de maio de 2014. As informações e opiniões contidas neste trabalho são de exclusiva responsabilidade do(s) autor(es). The Uses of Polyvinylidene Fluoride based resins in Chemical Handling Systems Denis K. de Almeidaa, Fabio L. F. Paganinib, David Seilerc Abstract Polyvinylidene fluoride (PVDF) based polymer resins have been used for corrosive and chemically aggressive fluid containment since 1964. In the 1980’s copolymers of vinylidene fluoride and hexafluoropropylene (HFP) were introduced that complimented the very rigid PVDF product line with a more flexible version of PVDF. Recently, other new technologies have been introduced for PVDF where it has been functionalized which allows it to be bonded to lower cost structural polymers during processing. Additionally, recent development of special grades of PVDF allow for finely woven and non-woven chemical filtration products and the creation of reliable conductive versions. Due to special properties not found in other plastics or metals, PVDF is used extensively in the following industries: chlor-alkali containment, bromine, acid production & distribution, mining, metal preparation, petrochemical, pharmaceutical, food & beverage, semiconductor, pulp & paper, waste water treatment, and power generation. This paper will outline the use of PVDF, reactive PVDF and/or PVDF based copolymers in specific chemicals and the special corrosive conditions that can be associated with them.
    [Show full text]
  • Self-Powered Multifunctional Motion Sensor Enabled by Magnetic
    Article Cite This: ACS Nano XXXX, XXX, XXX−XXX www.acsnano.org Self-Powered Multifunctional Motion Sensor Enabled by Magnetic-Regulated Triboelectric Nanogenerator † ‡ ⊥ † ⊥ † ⊥ † † † † Zhiyi Wu, , , Wenbo Ding, , Yejing Dai, , Kai Dong, Changsheng Wu, Lei Zhang, Zhiming Lin, † † § Jia Cheng, and Zhong Lin Wang*, , † School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, United States ‡ Engineering Research Center for Mechanical Testing Technology and Equipment of Ministry of Education, Chongqing University of Technology, Chongqing 400054, China § Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, China *S Supporting Information ABSTRACT: With the fast development of the Internet of Things, the requirements of system miniaturization and integration have accelerated research on multifunctional sensors. Based on the triboelectric nanogenerator, a self-powered multifunctional motion sensor (MFMS) is proposed in this work, which is capable of detecting the motion parameters, including direction, speed, and acceleration of linear and rotary motions, simultaneously. The MFMS consists of a triboelectric nanogenerator (TENG) module, a magnetic regulation module, and an acrylic shell. The TENG module is formed by placing a free-standing magnetic disk (MD) on a polytetrafluorethylene (PTFE) plate with six copper electrodes. The movement of the MFMS causes the MD to slide on the PTFE plate and hence excites the electrodes to produce a voltage output. The carefully designed six copper electrodes (an inner circle electrode, an outer circle electrode, and four arc electrodes between them) can distinguish eight directions of movement with the acceleration and determine the rotational speed and direction as well. Besides, the magnetic regulation module is applied here by fixing a magnetic cylinder (MC) in the shell, right under the center of the PTFE plate.
    [Show full text]
  • Time-Resolved Open-Circuit Conductive Atomic Force Microscopy for Quantitative Analysis of Nanowire Piezoelectricity and Triboelectricity
    Time-Resolved Open-Circuit Conductive Atomic Force Microscopy for Quantitative Analysis of Nanowire Piezoelectricity and Triboelectricity Yonatan Calahorra,1∗ Wonjong Kim,2 Jelena Vukajlovic-Plestina,2 Anna Fontcuberta i Morral,23 Sohini Kar-Narayan1 1Department of Materials Science and Metallurgy University of Cambridge, CB3 0FS, Cambrdige, UK 2Laboratory of Semiconductor Materials, Institute of Materials, School of Engineering Ecole polytechnique fed´ erale´ de Lausanne (EPFL), 1015 Lausanne, Switzerland 3Institute of Physics, School of Basic Sciences Ecole polytechnique fed´ erale´ de Lausanne (EPFL), 1015 Lausanne, Switzerland ∗To whom correspondence should be addressed; E-mail: [email protected] Piezoelectric nanowires are promising materials for sensing, actuation and en- ergy harvesting, due to their enhanced properties at the nanoscale. However, quantitative characterization of piezoelectricity in nanomaterials is challeng- ing due to practical limitations and the onset of additional electromechani- cal phenomena, such as the triboelectric and piezotronic effects. Here, we present an open-circuit conductive atomic force microscopy (cAFM) method- arXiv:1908.05512v4 [cond-mat.mes-hall] 2 Oct 2019 ology for quantitative extraction of the direct axial piezoelectric coefficients of nanowires. We show, both theoretically and experimentally, that the stan- dard short-circuit cAFM mode is inadequate for piezoelectric characterization of nanowires, and that such measurements are governed by competing mech- 1 anisms. We introduce an alternative open-circuit configuration, and employ time-resolved electromechanical measurements, to distinguish between elec- trical generation mechanisms and extract the piezoelectric coefficients. This method was applied to nanowires of GaAs, an important semiconductor, with relatively low piezoelectric coefficients. The results obtained for GaAs piezo- electric coefficient, ∼0.4-1 pm/V, are in good agreement with existing knowl- edge and theory.
    [Show full text]